Well localhost links don't make much sense ;)

redirect_to param controls where users go after logging in.
This is very easy if you create a plugin. You can also find where these hooks called and edit the core.

	function AfterUserRegistration( & $params )
	{
		global $redirect_to;
		$redirect_to = 'http://some/URL';
	}
	
	
	function ValidateAccountFormSent( & $params )
	{
		return $this->AfterUserRegistration( $params );
	}
	
	
	function AfterLoginRegisteredUser()
	{
		global $login_action, $redirect_to;
		
		if( !empty($login_action) )
		{
			$login_action = 'login';
			$redirect_to = 'http://some/URL';
		}
	}

Users should always see the evobar once they are logged in and granted access to backoffice. Check what you set in Group settings for that particular group.

Also what version of b2evo are you working on? Current development version already has "in skin" login and register pages. So if you don't mind playing using CVS version that may be a better way to go.

Here's a link to the nightly build.
http://doc.b2evolution.net/b2evo_HEAD_snapshot.tgz